Got the code p-0420 come up CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD what exactly does this mean and what can i do about it. No dealership near me so is there anything i can do?

 

It most likely means you need a new catalytic converter, they are covered under the 8 year 80k mile federal emissions warranty.

 

x2 and the code prob' also indicated that it is on bank2 (passenger side).

 

it says bank 1 .....i guess that means driver side?

 

Just had that code....and dazed is probably right. I have an 05 ram and i do know for a fact that they have a pcm emission upgrade which the dealer did for free because it fell under the 8 yr/80k emissions warranty. This fixed my code problem so far. Hope this helps

 

So the dealer replaced the cat for free since it was still under the 8yr/80k? That code has been flashing on and off in my truck for over a month now so I need to get it fixed. I already replaced the first oxygen sensor on the drivers side and that didn't fix it so idk?

 

Shadow11, no they didn't replace the cat, they just plugged into the pcm and uploaded some emission data. Like you, i replaced the driverside front 02 and then the 0420 code came back. I'd mention something to the dealer about it........my light still hasn't come back on

 

UPDATE......UPDATE...CEL came back on today, called a "different dealer". To make a long story short, he showed me the TB out on this code and it states to replace front and back 02 ALONG WITH CAT to fix problem so new cats are on the way. I got my fingers crossed

 

I've always been told cats don't go bad on thier own,it takes pollution from upstream to make the start going bad until they super heat and burn up inside. So if a cat goes bad you should be looking upstream for other problems,sensors,tec....

 

Don't really know of any "polution" coming from upstream. I burn atleast 89 and most the time 93. None the less, I'm putting the Cherry Bomb Vortex system on in the morning and hopefully the new cats by early week.